{"gene":"PRKN","run_date":"2026-06-10T06:43:35","timeline":{"discoveries":[{"year":2008,"finding":"Parkin is selectively recruited from the cytosol to dysfunctional mitochondria with low membrane potential, after which it mediates engulfment of mitochondria by autophagosomes and their selective elimination (mitophagy).","method":"Live-cell imaging and mitochondrial membrane potential assays in mammalian cells with Parkin overexpression/loss-of-function","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — foundational direct localization experiment with functional consequence (mitophagy readout), replicated extensively across many subsequent labs","pmids":["19029340"],"is_preprint":false},{"year":2010,"finding":"PINK1 accumulates selectively on damaged (depolarized) mitochondria via voltage-dependent proteolysis; PINK1 accumulation is both necessary and sufficient for Parkin recruitment to mitochondria, placing PINK1 upstream of Parkin in a linear epistatic pathway controlling mitophagy. Disease-causing mutations in PINK1 and Parkin disrupt Parkin recruitment at distinct steps.","method":"Genetic epistasis (PINK1/Parkin mutant cell lines), fluorescence microscopy, biochemical fractionation, Drosophila genetic rescue","journal":"PLoS biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods, epistasis defined, replicated across labs","pmids":["20126261"],"is_preprint":false},{"year":2015,"finding":"Crystal structure of Parkin (Pediculus humanus ortholog) in complex with Ser65-phosphorylated ubiquitin (phosphoUb) reveals: (1) a conserved phosphate-binding pocket on RING1 that docks phosphoUb; (2) phosphoUb binding straightens a RING1 helix causing conformational changes that release the Ubl domain from the Parkin core; (3) Ubl release exposes Ubl Ser65 to PINK1 phosphorylation; (4) Ubl phosphorylation further stabilizes an open, active Parkin conformation. The Ubl domain acts as both an inhibitory and activating element.","method":"X-ray crystallography, mutagenesis, biochemical ubiquitination assays","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure plus mutagenesis plus functional assays in a single rigorous study","pmids":["26161729"],"is_preprint":false},{"year":2018,"finding":"Full activation mechanism of Parkin: hydrogen-deuterium exchange MS reveals large-scale domain rearrangement upon PINK1-mediated phosphorylation; the phospho-Ubl rebinds to the Parkin core at the unique parkin domain (UPD) using a phosphate-binding pocket (lined by AR-JP mutations), releasing the catalytic RING2 domain. A conserved linker 'activating element' (ACT) between Ubl and UPD mimics RING2 interactions to aid RING2 release. 1.8 Å crystal structure of phosphorylated human Parkin confirms this binding site.","method":"Hydrogen-deuterium exchange mass spectrometry, X-ray crystallography (1.8 Å), mutagenesis","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple orthogonal structural and biophysical methods, full-length human Parkin, rigorous mutagenesis validation","pmids":["29995846"],"is_preprint":false},{"year":2018,"finding":"Crystal structure of phosphorylated Bactrocera dorsalis Parkin in complex with phospho-ubiquitin and an E2 ubiquitin-conjugating enzyme reveals the key activating step: movement of the phospho-Ubl domain and release of the catalytic RING2 domain. HDX and NMR experiments confirm this mechanism extends to mammalian Parkin.","method":"X-ray crystallography, hydrogen/deuterium exchange, NMR, in vitro ubiquitination assays","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple orthogonal structural/biophysical methods, functional validation, independent replication of activation mechanism","pmids":["29967542"],"is_preprint":false},{"year":2018,"finding":"Parkin and PINK1-mediated mitophagy restrains innate immunity (STING-dependent type I interferon response). In Prkn−/− mice, exhaustive exercise or mtDNA mutation triggers inflammation that is completely rescued by concurrent STING loss. Loss of dopaminergic neurons and motor defects in aged Prkn−/−;mutator mice are also rescued by STING deletion.","method":"Mouse knockout models (Prkn−/−, Pink1−/−, STING−/−), exhaustive exercise stress, mtDNA mutator mouse, behavioral and histological analyses, cytokine measurements","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean genetic epistasis in multiple in vivo models, multiple orthogonal readouts, highly cited","pmids":["30135585"],"is_preprint":false},{"year":2015,"finding":"BNIP3L/Nix is a substrate of PARK2/Parkin; Parkin ubiquitinates BNIP3L, which recruits NBR1 to mitochondria to target them for degradation. BNIP3L rescues mitochondrial defects in pink1 mutant Drosophila but not in park mutant Drosophila, placing BNIP3L downstream of Parkin.","method":"Co-immunoprecipitation, ubiquitination assays, Drosophila genetic rescue, knockdown/overexpression in mammalian cells","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus genetic epistasis in Drosophila, single lab","pmids":["25612572"],"is_preprint":false},{"year":2016,"finding":"Parkin interacts with and ubiquitinates pyruvate kinase M2 (PKM2) both in vitro and in vivo; ubiquitination does not affect PKM2 stability but decreases its enzymatic activity, thereby regulating glycolysis. The interaction is enhanced during glucose starvation.","method":"Biochemical purification, Co-IP (in vitro and in vivo), ubiquitination assay, enzymatic activity assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro and in vivo Co-IP plus enzymatic activity assay, single lab","pmids":["26975375"],"is_preprint":false},{"year":2016,"finding":"PINK1 phosphorylation of Miro on S156 promotes Parkin interaction with Miro, stimulates Miro ubiquitination and degradation, recruits Parkin to mitochondria, and via Parkin arrests axonal transport of mitochondria. Phosphomimetic T298E/T299E on Miro inhibits PINK1-induced Miro ubiquitination and Parkin recruitment, acting dominantly over S156E.","method":"Phosphomimetic mutations, Co-IP, ubiquitination assays, axonal transport imaging in neurons","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — phosphomimetic mutagenesis plus functional transport assay, single lab","pmids":["27679849"],"is_preprint":false},{"year":2018,"finding":"Miro1 serves as a calcium-sensitive docking site for Parkin on mitochondria: a small pool of Parkin interacts with Miro1 before mitochondrial damage occurs, independently of PINK1 and without ubiquitination. After damage and PINK1 accumulation, this Parkin pool is activated, leading to Miro1 ubiquitination and degradation. Knockdown of Miro proteins reduces Parkin translocation and mitophagy. Miro1 EF-hand (calcium-sensing) domains control Miro1 ubiquitination and Parkin recruitment.","method":"Co-immunoprecipitation, fluorescence imaging, siRNA knockdown, EF-hand domain mutagenesis, mitophagy assays","journal":"The EMBO journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus domain mutagenesis plus mitophagy readout, single lab","pmids":["30504269"],"is_preprint":false},{"year":2019,"finding":"USP33/VDU1 is a deubiquitinase for Parkin, localizes to the outer mitochondrial membrane, and removes K6-, K11-, K48-, and K63-linked ubiquitin conjugates from Parkin, predominantly at Lys435. USP33 knockdown increases both K48- and K63-linked Parkin ubiquitination, stabilizes Parkin, and enhances its translocation to depolarized mitochondria, increasing mitophagy.","method":"Co-IP, in vitro deubiquitination assays, site-directed mutagenesis (K435R), siRNA knockdown, mitophagy assays","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro DUB assay plus mutagenesis plus cellular mitophagy readout, single lab","pmids":["31432739"],"is_preprint":false},{"year":2015,"finding":"USP8 deubiquitinase interacts with Parkin and preferentially removes K6-linked ubiquitin conjugates from Parkin. USP8 silencing leads to persistence of K6-linked Parkin ubiquitin conjugates, delaying Parkin translocation to damaged mitochondria and completion of mitophagy.","method":"Co-IP, ubiquitin linkage analysis, USP8 siRNA knockdown, mitophagy assays","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus functional mitophagy assay, single lab","pmids":["25700639"],"is_preprint":false},{"year":2020,"finding":"VDAC1 is ubiquitinated by Parkin in a PINK1-dependent manner in two modes: monoubiquitination (at K274) and polyubiquitination. Polyubiquitination deficiency impairs mitophagy. Monoubiquitination deficiency (K274R) promotes apoptosis by augmenting mitochondrial calcium uptake through the MCU channel. A PD patient mutation T415N in Parkin lacks VDAC1 monoubiquitination activity while retaining polyubiquitination, and fails to rescue PD phenotypes in Drosophila.","method":"Ubiquitination assays, site-directed mutagenesis, calcium imaging, Drosophila transgenic models, patient mutation analysis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis plus in vivo Drosophila model plus calcium uptake assay, single lab","pmids":["32047033"],"is_preprint":false},{"year":2018,"finding":"RABGEF1, an upstream regulator of the endosomal Rab GTPase cascade, is recruited to damaged mitochondria via ubiquitin binding downstream of Parkin. RABGEF1 directs RAB5 and RAB7A to damaged mitochondria; RAB7A depletion inhibits ATG9A vesicle assembly and subsequent encapsulation of mitochondria by autophagic membranes.","method":"siRNA knockdown, Co-IP, fluorescence microscopy in mammalian cultured cells, mitophagy assays","journal":"eLife","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus functional mitophagy readout with multiple knockdowns, single lab","pmids":["29360040"],"is_preprint":false},{"year":2019,"finding":"PHB2 (prohibitin 2, inner mitochondrial membrane protein) is required for PINK1 stabilization on mitochondria and subsequent Parkin recruitment. PHB2 depletion destabilizes PINK1 and blocks Parkin, ubiquitin, and OPTN recruitment. The mechanism involves the PARL protease (activated upon PHB2 depletion) and PGAM5 (processed by PARL), defining a PHB2-PARL-PGAM5-PINK1 axis upstream of Parkin.","method":"siRNA knockdown, overexpression, Co-IP, fluorescence microscopy, mitophagy assays in MEFs and cancer cells","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple knockdown/overexpression experiments with mechanistic epistasis, single lab","pmids":["31177901"],"is_preprint":false},{"year":2012,"finding":"Parkin is neddylated (conjugated with NEDD8), and neddylation increases Parkin's E3 ligase activity. The PD neurotoxin MPP+ inhibits neddylation of Parkin. Expression of dAPP-BP1 (NEDD8 activation enzyme subunit) in Drosophila suppresses abnormalities induced by dPINK1 RNAi.","method":"Neddylation assays, E3 ligase activity assay, MPP+ treatment, Drosophila genetics","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — biochemical neddylation assay plus Drosophila genetic rescue, single lab","pmids":["22388932"],"is_preprint":false},{"year":2008,"finding":"Combined phosphorylation of Parkin by both casein kinase I and cyclin-dependent kinase 5 (Cdk5) decreases Parkin solubility, causing its aggregation and inactivation. Combined kinase inhibition partially reverses aggregation of pathogenic Parkin point mutants in cultured cells. Enhanced Parkin phosphorylation is detected in brain areas of sporadic PD patients, correlating with elevated p25 (Cdk5 activator) levels.","method":"Kinase activity assays, solubility fractionation, cell-based aggregation assays, immunohistochemistry of PD brain tissue","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in-cell kinase assays plus PD patient tissue, single lab","pmids":["19050041"],"is_preprint":false},{"year":2003,"finding":"Parkin ubiquitinates the Pael (parkin-associated endothelin receptor-like) receptor, an ER-resident protein prone to unfolding, using ER-resident E2s, and promotes its degradation, thereby suppressing ER stress-induced cell death. Insoluble Pael receptor accumulates in AR-JP patient brains.","method":"Yeast two-hybrid, in vitro ubiquitination assay with ER-resident E2s, cell death assays, post-mortem patient brain analysis","journal":"Annals of the New York Academy of Sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro ubiquitination assay plus cell-based rescue plus patient tissue, single lab","pmids":["12846978"],"is_preprint":false},{"year":2009,"finding":"Parkin promotes ubiquitination and proteasomal degradation of intracellular Aβ1-42. Parkin expression reduces intracellular Aβ1-42 levels and protects against its toxicity; incubation of Aβ1-42 cell lysates with ubiquitin in the presence of Parkin generates Aβ-ubiquitin complexes. Proteasomal inhibition blocks Parkin's effect on Aβ levels.","method":"Lentiviral overexpression, ubiquitination assay, proteasome inhibition, in vivo co-injection in rat motor cortex","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ubiquitination assay plus proteasome inhibition plus in vivo validation, single lab","pmids":["19483198"],"is_preprint":false},{"year":2009,"finding":"Parkin is essential for optimal DNA excision repair; parkin-deficient cells show reduced DNA excision repair restored by wild-type but not pathological mutant Parkin. Parkin interacts with PCNA (proliferating cell nuclear antigen), a coordinator of DNA excision repair.","method":"DNA repair assays, Co-IP with PCNA, transfection of wild-type vs. mutant Parkin, cell viability assays","journal":"Biochemical and biophysical research communications","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP plus repair assay, single lab, not replicated","pmids":["19285961"],"is_preprint":false},{"year":2016,"finding":"PARK2/Parkin directly binds to and ubiquitinates BCL-XL, leading to its degradation. Inactivation of PARK2 leads to aberrant accumulation of BCL-XL in vitro and in vivo; cancer-specific PARK2 mutations abrogate BCL-XL ubiquitination. PARK2 modulates mitochondrial depolarization and apoptosis in a BCL-XL-dependent manner.","method":"Co-IP, ubiquitination assays, in vivo mouse models, cancer mutant analysis","journal":"Neoplasia","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus ubiquitination assay plus in vivo model plus mutant analysis, single lab","pmids":["28038320"],"is_preprint":false},{"year":2021,"finding":"MITOL/MARCH5 (mitochondrial ubiquitin ligase) ubiquitinates Parkin at lysine 220, promoting its proteasomal degradation. MITOL deletion leads to accumulation of phosphorylated active Parkin in the ER, resulting in FKBP38 degradation and enhanced cell death. MITOL thereby fine-tunes mitophagy by controlling Parkin quantity and blocks Parkin-induced cell death by protecting FKBP38.","method":"Ubiquitination assays, site-directed mutagenesis (K220), MITOL deletion cell lines, immunofluorescence, cell death assays","journal":"EMBO reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis plus KO cell lines plus functional readouts, single lab","pmids":["33565245"],"is_preprint":false},{"year":2023,"finding":"PA2G4/EBP1 is ubiquitinated on lysine 376 by PRKN/Parkin on damaged mitochondria; ubiquitinated PA2G4 then interacts with SQSTM1/p62 to induce mitophagy, protecting neurons from cerebral ischemia-reperfusion injury.","method":"Co-IP, ubiquitination assay with site-directed mutagenesis (K376), neuron-specific knockout mice (MCAO model), AAV rescue","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis plus in vivo KO model plus rescue, single lab","pmids":["37712850"],"is_preprint":false},{"year":2014,"finding":"Parkin promotes Drp1-dependent mitochondrial fission by a mechanism requiring dephosphorylation of Drp1 serine 637 via the calcium/calmodulin/calcineurin pathway. Drp1 and Parkin are co-recruited to mitochondria in proximity of PINK1 following depolarization (FRET imaging). The outer mitochondrial adaptor MiD51 plays a major role in Drp1 recruitment and Parkin-dependent mitophagy.","method":"FRET imaging, calcineurin pathway inhibitors, Parkin/PINK1 mutant cell lines, mitochondrial morphology analysis","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — FRET imaging plus pharmacological pathway dissection, single lab","pmids":["24878071"],"is_preprint":false},{"year":2022,"finding":"Park2-deficient white adipocytes show reduced mitophagy but increased mitochondrial DNA content and mitochondrial function due to elevated mitochondrial biogenesis via Pgc1α stabilization through mitochondrial superoxide-activated Nqo1. Parkin therefore balances mitophagy and Pgc1α-mediated mitochondrial biogenesis in white adipocytes.","method":"Adipose tissue-specific Park2 knockout mice, mitophagy assays, Nqo1 overexpression, in vitro and in vivo metabolic assays","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — tissue-specific KO plus mechanistic pathway dissection, single lab","pmids":["36333379"],"is_preprint":false},{"year":2024,"finding":"Small molecule allosteric modulators act as 'molecular glues' enhancing phospho-ubiquitin (pUb) binding to and activation of Parkin. Crystal structure of Parkin–pUb complex with compound BIO-1975900 shows it binds next to pUb on RING0, contacting both proteins. HDX-MS confirms activation occurs via release of the catalytic Rcat domain. The compounds partially rescue activity of EOPD Parkin mutants R42P and V56E in organello and mitophagy assays.","method":"X-ray crystallography, isothermal titration calorimetry, ubiquitination assays, HDX-MS, organello and cell-based mitophagy assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure plus multiple biophysical methods plus functional assays with disease mutants, single rigorous study","pmids":["39300082"],"is_preprint":false},{"year":2006,"finding":"Parkin ubiquitinates synphilin-1 (the α-synuclein interacting protein); co-expression of α-synuclein, synphilin-1, and Parkin forms Lewy-body-like ubiquitin-positive cytosolic inclusions. Nitric oxide inhibits Parkin's E3 ligase activity and its neuroprotective function via S-nitrosylation both in vitro and in vivo.","method":"Ubiquitination assays, co-transfection/inclusion body formation assay, S-nitrosylation assay in vitro and in vivo","journal":"Journal of neural transmission. Supplementum","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple biochemical assays in vitro and in vivo, single review but citing primary experimental work","pmids":["17017531"],"is_preprint":false},{"year":2020,"finding":"Bcl-xL physically binds Parkin in the cytoplasm (FRET imaging) and also directly interacts with PINK1 on mitochondria (Co-IP), thereby inhibiting PINK1/Parkin-dependent mitophagy by preventing Parkin accumulation on mitochondria via two mechanisms: (1) cytoplasmic sequestration of Parkin, and (2) interference with PINK1 on the outer mitochondrial membrane.","method":"Co-IP, FRET imaging, FLIP analysis, Western blot, fluorescence microscopy in HeLa and HEK293T cells","journal":"The international journal of biochemistry & cell biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — Co-IP and FRET in single lab, no mutagenesis or reconstitution","pmids":["32088314"],"is_preprint":false},{"year":2017,"finding":"Parkin accelerates microtubule aging in its absence: PARK2 knockout mice show accelerated over-acetylation of the microtubule system in dopaminergic neurons and fibers, preceding mitochondrial transport defects. Parkin deficiency causes fragmentation of stable microtubules in PC12 cells and iPSC-derived midbrain neurons. Paclitaxel (microtubule-stabilizing agent) rescues mitochondrial mobility defects caused by Parkin loss.","method":"PARK2 KO mouse histology, immunofluorescence of acetylated tubulin, mitochondrial transport assays, paclitaxel rescue, iPSC-derived neurons","journal":"Neurobiology of aging","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo KO model plus cell-based rescue, single lab, two orthogonal model systems","pmids":["29040870"],"is_preprint":false},{"year":2001,"finding":"Parkin functions as a RING-type E3 ubiquitin ligase (via its RING-IBR-RING motif), collaborating with E2 ubiquitin-conjugating enzymes UbcH7 or UbcH8. AR-JP patient mutations abolish parkin's E3 ligase activity. CDCrel-1, a synaptic vesicle-associated protein, was identified as a substrate for Parkin.","method":"In vitro ubiquitination assays with purified components, patient mutation analysis, substrate identification by biochemical pulldown","journal":"Journal of molecular medicine (Berlin, Germany)","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution of E3 ligase activity, established by multiple labs","pmids":["11692161"],"is_preprint":false}],"current_model":"Parkin is an RBR-type E3 ubiquitin ligase that is maintained in an autoinhibited conformation; upon mitochondrial damage, PINK1 accumulates on depolarized mitochondria and phosphorylates ubiquitin (Ser65) and the Parkin ubiquitin-like (Ubl) domain (Ser65), causing phospho-ubiquitin to bind RING0 and release the Ubl, which then rebinds the unique parkin domain (UPD) via an activating element to liberate the catalytic RING2 domain, enabling Parkin to ubiquitinate outer mitochondrial membrane substrates (including Mfn1/2, Miro, VDAC1, BNIP3L, and others) and recruit autophagy receptors, thereby triggering selective mitophagy that suppresses STING-dependent innate immune activation; Parkin activity is further modulated by deubiquitinases (USP8 removing K6-linked, USP33 removing multiple linkages), by neddylation (increasing activity), by S-nitrosylation and phosphorylation by CKI/Cdk5 (inactivating), and by MITOL-mediated ubiquitination at K220 (promoting its own proteasomal degradation); beyond mitophagy, Parkin ubiquitinates additional substrates including BCL-XL, PKM2, synphilin-1, PCNA-associated repair proteins, and Aβ1-42, and also acts as a transcription factor, underscoring its multifunctional role in neuronal homeostasis and Parkinson's disease pathogenesis."},"narrative":{"mechanistic_narrative":"PRKN/Parkin is a RING-IBR-RING (RBR)-type E3 ubiquitin ligase that operates as the effector arm of a quality-control pathway clearing damaged mitochondria by selective autophagy (mitophagy), with loss-of-function mutations causing autosomal-recessive juvenile Parkinsonism [PMID:19029340, PMID:11692161]. Parkin catalyzes ubiquitin transfer in collaboration with E2 conjugating enzymes (UbcH7/UbcH8), and AR-JP patient mutations abolish this activity [PMID:11692161]. Mitochondrial depolarization causes PINK1 to accumulate on damaged organelles, where it is both necessary and sufficient to recruit cytosolic Parkin, placing PINK1 directly upstream in a linear pathway [PMID:20126261]. Activation is conformational: PINK1 phosphorylates ubiquitin and the Parkin ubiquitin-like (Ubl) domain at Ser65; phospho-ubiquitin docks a RING1 pocket to release the autoinhibitory Ubl, and the phospho-Ubl then rebinds the unique parkin domain via a conserved activating element, liberating the catalytic RING2/Rcat domain for ubiquitin transfer [PMID:26161729, PMID:29995846, PMID:29967542]. Once activated on the outer mitochondrial membrane, Parkin ubiquitinates a series of substrates including Miro1, VDAC1, and BNIP3L/Nix to mark mitochondria for clearance, arrest their axonal transport, and recruit autophagy receptors and the endosomal Rab cascade (RABGEF1–RAB5/RAB7A) that drives autophagic engulfment [PMID:25612572, PMID:27679849, PMID:30504269, PMID:32047033, PMID:29360040]. This mitophagy program restrains STING-dependent type I interferon innate immunity, and its failure drives inflammation and dopaminergic neuron loss in vivo [PMID:30135585]. Parkin activity is tuned by deubiquitinases that reverse its self-ubiquitination (USP8 removing K6-linked, USP33 removing multiple linkages to stabilize Parkin) [PMID:31432739, PMID:25700639], by activating neddylation [PMID:22388932], and by inactivating modifications including CKI/Cdk5 phosphorylation and S-nitrosylation [PMID:19050041, PMID:17017531]; MITOL/MARCH5 ubiquitinates Parkin at K220 to control its abundance [PMID:33565245]. Beyond mitophagy, Parkin ubiquitinates additional substrates affecting metabolism and survival, including PKM2, BCL-XL, the Pael receptor, synphilin-1, and intracellular Aβ1-42 [PMID:26975375, PMID:12846978, PMID:19483198, PMID:28038320, PMID:17017531]. Small-molecule 'molecular glues' that enhance phospho-ubiquitin binding to RING0 can pharmacologically activate Parkin and partially rescue early-onset PD mutants [PMID:39300082].","teleology":[{"year":2001,"claim":"Established Parkin's core biochemical identity as a RING-type E3 ubiquitin ligase whose activity is destroyed by disease mutations, defining the molecular lesion in AR-JP.","evidence":"In vitro ubiquitination reconstitution with purified components, E2 pairing, and patient mutation analysis","pmids":["11692161"],"confidence":"High","gaps":["CDCrel-1 substrate relevance to neurodegeneration unresolved","did not define the physiological trigger for ligase activity"]},{"year":2008,"claim":"Revealed that Parkin's function is spatially gated — it is recruited from cytosol specifically to depolarized mitochondria and drives their autophagic elimination, linking the ligase to organelle quality control.","evidence":"Live-cell imaging and membrane-potential assays in mammalian cells","pmids":["19029340"],"confidence":"High","gaps":["did not identify the upstream sensor of damage","OMM substrates ubiquitinated for mitophagy not yet mapped"]},{"year":2010,"claim":"Placed PINK1 upstream of Parkin by showing voltage-dependent PINK1 accumulation is necessary and sufficient for Parkin recruitment, defining a linear PINK1–Parkin mitophagy pathway.","evidence":"Genetic epistasis, microscopy, fractionation, Drosophila rescue","pmids":["20126261"],"confidence":"High","gaps":["molecular signal transmitted from PINK1 to Parkin unknown at this stage","did not resolve the conformational activation mechanism"]},{"year":2015,"claim":"Solved how phospho-ubiquitin acts as the activating ligand, docking RING1 to release the autoinhibitory Ubl and exposing Ubl Ser65 for further phosphorylation — explaining the feed-forward activation switch.","evidence":"X-ray crystallography of Parkin–phosphoUb complex with mutagenesis and ubiquitination assays","pmids":["26161729"],"confidence":"High","gaps":["did not show fate of released RING2 catalytic domain","ortholog structure required mammalian confirmation"]},{"year":2018,"claim":"Completed the activation model by showing the phospho-Ubl rebinds the UPD via a conserved activating element to release the catalytic RING2/Rcat domain, with full-length human and insect structures plus E2 capture.","evidence":"HDX-MS, 1.8 Å and complex crystallography, NMR, mutagenesis, in vitro ubiquitination","pmids":["29995846","29967542"],"confidence":"High","gaps":["substrate engagement geometry on the mitochondrial surface not resolved","kinetics of activation in cellulo not quantified"]},{"year":2018,"claim":"Identified downstream effectors converting Parkin ubiquitination into autophagic engulfment, recruiting the RABGEF1–RAB5/RAB7A endosomal cascade and ATG9A vesicle assembly to damaged mitochondria.","evidence":"siRNA knockdown, Co-IP, microscopy, mitophagy assays in cultured cells","pmids":["29360040"],"confidence":"Medium","gaps":["single lab; direct ubiquitin substrate recruiting RABGEF1 not defined","reciprocal validation absent"]},{"year":2018,"claim":"Resolved the upstream control of PINK1 stability, defining a PHB2–PARL–PGAM5 axis required to stabilize PINK1 and thereby permit Parkin and OPTN recruitment.","evidence":"Knockdown/overexpression epistasis, Co-IP, microscopy, mitophagy assays","pmids":["31177901"],"confidence":"Medium","gaps":["single lab","direct biochemical interactions within the axis not fully reconstituted"]},{"year":2016,"claim":"Defined Miro as both a docking platform and a substrate, showing PINK1 phosphorylation of Miro promotes Parkin binding, Miro ubiquitination/degradation and arrest of mitochondrial axonal transport.","evidence":"Phosphomimetic mutagenesis, Co-IP, ubiquitination assays, axonal transport imaging; plus calcium-sensitive docking via Miro1 EF-hands","pmids":["27679849","30504269"],"confidence":"Medium","gaps":["single lab per study","stoichiometry of the pre-damage Parkin–Miro pool unclear"]},{"year":2020,"claim":"Showed VDAC1 ubiquitination is dual-mode, with mono- versus poly-ubiquitination separating mitophagy from calcium/apoptosis control, validated by a PD mutation selectively losing monoubiquitination.","evidence":"Mutagenesis, calcium imaging, Drosophila models, patient mutation analysis","pmids":["32047033"],"confidence":"Medium","gaps":["single lab","mechanism linking monoUb to MCU calcium flux not fully defined"]},{"year":2018,"claim":"Connected Parkin-driven mitophagy to suppression of innate immunity, showing STING deletion rescues inflammation and dopaminergic neuron loss in Prkn-deficient stressed mice.","evidence":"Multiple mouse knockout models, exercise/mtDNA-mutator stress, behavioral and histological readouts","pmids":["30135585"],"confidence":"High","gaps":["molecular route from defective mitophagy to STING activation not fully detailed","human relevance of the inflammatory axis untested here"]},{"year":2021,"claim":"Identified regulators tuning Parkin levels and modification state — deubiquitinases (USP8, USP33), activating neddylation, inactivating CKI/Cdk5 phosphorylation and S-nitrosylation, and MITOL-mediated K220 ubiquitination controlling Parkin turnover.","evidence":"Deubiquitination/neddylation/kinase assays, mutagenesis, KO cell lines, mitophagy and cell-death readouts, PD tissue","pmids":["25700639","31432739","22388932","19050041","17017531","33565245"],"confidence":"Medium","gaps":["each modification largely from a single lab","integrated hierarchy of these regulatory inputs unresolved"]},{"year":2023,"claim":"Expanded Parkin's substrate repertoire beyond canonical mitophagy to metabolic, apoptotic, ER-stress, and proteostatic targets (PKM2, BCL-XL, Pael receptor, synphilin-1, Aβ1-42, PA2G4, BNIP3L), broadening its role in neuronal and metabolic homeostasis.","evidence":"Co-IP, ubiquitination assays, in vivo KO/rescue models across multiple studies","pmids":["26975375","28038320","12846978","17017531","19483198","37712850","25612572"],"confidence":"Medium","gaps":["substrate specificity determinants in vivo unclear","relative physiological weight of mitophagy versus non-mitochondrial substrates unresolved"]},{"year":2024,"claim":"Demonstrated Parkin is pharmacologically tractable, with small-molecule molecular glues enhancing phospho-ubiquitin binding at RING0 to activate the enzyme and partially rescue early-onset PD mutants.","evidence":"Crystallography, ITC, HDX-MS, ubiquitination and mitophagy assays with disease mutants","pmids":["39300082"],"confidence":"High","gaps":["in vivo efficacy and selectivity not established","rescue of only a subset of disease mutants"]},{"year":null,"claim":"How Parkin's diverse substrate selection and regulatory modifications are integrated in vivo to balance mitophagy, mitochondrial biogenesis, metabolism, and neuronal survival remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["no unified model ranking the physiological importance of competing substrates","tissue-specific regulatory hierarchy of activating/inactivating modifications undefined","structural basis of substrate engagement on the mitochondrial surface unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[29,2,3]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[29,6,7,12,20]},{"term_id":"GO:0031386","term_label":"protein tag activity","supporting_discovery_ids":[29,6,12]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[25]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,9,27]},{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[0,1,9,12]}],"pathway":[{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[0,1,6,13]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[23,24]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[5]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[29,10,21]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[20,21,12]}],"complexes":[],"partners":["PINK1","MIRO1","VDAC1","BNIP3L","BCL-XL","USP8","USP33","PKM2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O60260","full_name":"E3 ubiquitin-protein ligase parkin","aliases":["Parkin RBR E3 ubiquitin-protein ligase","Parkinson juvenile disease protein 2","Parkinson disease protein 2"],"length_aa":465,"mass_kda":51.6,"function":"Functions within a multiprotein E3 ubiquitin ligase complex, catalyzing the covalent attachment of ubiquitin moieties onto substrate proteins (PubMed:10888878, PubMed:10973942, PubMed:11431533, PubMed:12150907, PubMed:12628165, PubMed:15105460, PubMed:16135753, PubMed:21376232, PubMed:21532592, PubMed:22396657, PubMed:23620051, PubMed:23754282, PubMed:24660806, PubMed:24751536, PubMed:29311685, PubMed:32047033). Substrates include SYT11 and VDAC1 (PubMed:29311685, PubMed:32047033). Other substrates are BCL2, CCNE1, GPR37, RHOT1/MIRO1, MFN1, MFN2, STUB1, SNCAIP, SEPTIN5, TOMM20, USP30, ZNF746, MIRO1 and AIMP2 (PubMed:10888878, PubMed:10973942, PubMed:11431533, PubMed:12150907, PubMed:12628165, PubMed:15105460, PubMed:16135753, PubMed:21376232, PubMed:21532592, PubMed:22396657, PubMed:23620051, PubMed:23754282, PubMed:24660806, PubMed:24751536). Mediates monoubiquitination as well as 'Lys-6', 'Lys-11', 'Lys-48'-linked and 'Lys-63'-linked polyubiquitination of substrates depending on the context (PubMed:19229105, PubMed:20889974, PubMed:25474007, PubMed:25621951, PubMed:32047033). Participates in the removal and/or detoxification of abnormally folded or damaged protein by mediating 'Lys-63'-linked polyubiquitination of misfolded proteins such as PARK7: 'Lys-63'-linked polyubiquitinated misfolded proteins are then recognized by HDAC6, leading to their recruitment to aggresomes, followed by degradation (PubMed:17846173, PubMed:19229105). Mediates 'Lys-63'-linked polyubiquitination of a 22 kDa O-linked glycosylated isoform of SNCAIP, possibly playing a role in Lewy-body formation (PubMed:11431533, PubMed:11590439, PubMed:15105460, PubMed:15728840, PubMed:19229105). Mediates monoubiquitination of BCL2, thereby acting as a positive regulator of autophagy (PubMed:20889974). Protects against mitochondrial dysfunction during cellular stress, by acting downstream of PINK1 to coordinate mitochondrial quality control mechanisms that remove and replace dysfunctional mitochondrial components (PubMed:11439185, PubMed:18957282, PubMed:19029340, PubMed:19966284, PubMed:21376232, PubMed:22082830, PubMed:22396657, PubMed:23620051, PubMed:23933751, PubMed:24660806, PubMed:24784582, PubMed:24896179, PubMed:25474007, PubMed:25527291, PubMed:32047033). Depending on the severity of mitochondrial damage and/or dysfunction, activity ranges from preventing apoptosis and stimulating mitochondrial biogenesis to regulating mitochondrial dynamics and eliminating severely damaged mitochondria via mitophagy (PubMed:11439185, PubMed:19029340, PubMed:19801972, PubMed:19966284, PubMed:21376232, PubMed:22082830, PubMed:22396657, PubMed:23620051, PubMed:23685073, PubMed:23933751, PubMed:24896179, PubMed:25527291, PubMed:32047033, PubMed:33499712). Activation and recruitment onto the outer membrane of damaged/dysfunctional mitochondria (OMM) requires PINK1-mediated phosphorylation of both PRKN and ubiquitin (PubMed:24660806, PubMed:24784582, PubMed:25474007, PubMed:25527291). After mitochondrial damage, functions with PINK1 to mediate the decision between mitophagy or preventing apoptosis by inducing either the poly- or monoubiquitination of VDAC1, respectively; polyubiquitination of VDAC1 promotes mitophagy, while monoubiquitination of VDAC1 decreases mitochondrial calcium influx which ultimately inhibits apoptosis (PubMed:27534820, PubMed:32047033). When cellular stress results in irreversible mitochondrial damage, promotes the autophagic degradation of dysfunctional depolarized mitochondria (mitophagy) by promoting the ubiquitination of mitochondrial proteins such as TOMM20, RHOT1/MIRO1, MFN1 and USP30 (PubMed:19029340, PubMed:19966284, PubMed:21753002, PubMed:22396657, PubMed:23620051, PubMed:23685073, PubMed:23933751, PubMed:24896179, PubMed:25527291). Preferentially assembles 'Lys-6'-, 'Lys-11'- and 'Lys-63'-linked polyubiquitin chains, leading to mitophagy (PubMed:25621951, PubMed:32047033). The PINK1-PRKN pathway also promotes fission of damaged mitochondria by PINK1-mediated phosphorylation which promotes the PRKN-dependent degradation of mitochondrial proteins involved in fission such as MFN2 (PubMed:23620051). This prevents the refusion of unhealthy mitochondria with the mitochondrial network or initiates mitochondrial fragmentation facilitating their later engulfment by autophagosomes (PubMed:23620051). Regulates motility of damaged mitochondria via the ubiquitination and subsequent degradation of MIRO1 and MIRO2; in motor neurons, this likely inhibits mitochondrial intracellular anterograde transport along the axons which probably increases the chance of the mitochondria undergoing mitophagy in the soma (PubMed:22396657). Involved in mitochondrial biogenesis via the 'Lys-48'-linked polyubiquitination of transcriptional repressor ZNF746/PARIS which leads to its subsequent proteasomal degradation and allows activation of the transcription factor PPARGC1A (PubMed:21376232). Limits the production of reactive oxygen species (ROS) (PubMed:18541373). Regulates cyclin-E during neuronal apoptosis (PubMed:12628165). In collaboration with CHPF isoform 2, may enhance cell viability and protect cells from oxidative stress (PubMed:22082830). Independently of its ubiquitin ligase activity, protects from apoptosis by the transcriptional repression of p53/TP53 (PubMed:19801972). May protect neurons against alpha synuclein toxicity, proteasomal dysfunction, GPR37 accumulation, and kainate-induced excitotoxicity (PubMed:11439185). May play a role in controlling neurotransmitter trafficking at the presynaptic terminal and in calcium-dependent exocytosis. May represent a tumor suppressor gene (PubMed:12719539)","subcellular_location":"Cytoplasm, cytosol; Nucleus; Endoplasmic reticulum; Mitochondrion; Mitochondrion outer membrane; Cell projection, neuron projection; Postsynaptic density; Presynapse","url":"https://www.uniprot.org/uniprotkb/O60260/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PRKN","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/PRKN","total_profiled":1310},"omim":[{"mim_id":"620808","title":"SMALL NUCLEOLAR RNA HOST GENE 17; SNHG17","url":"https://www.omim.org/entry/620808"},{"mim_id":"620069","title":"ANKYRIN REPEAT- AND IBR DOMAIN-CONTAINING PROTEIN 1; ANKIB1","url":"https://www.omim.org/entry/620069"},{"mim_id":"617081","title":"OMA1 ZINC METALLOPEPTIDASE; OMA1","url":"https://www.omim.org/entry/617081"},{"mim_id":"616032","title":"FOCAL SEGMENTAL GLOMERULOSCLEROSIS 8; FSGS8","url":"https://www.omim.org/entry/616032"},{"mim_id":"616027","title":"ACTIN-BINDING PROTEIN ANILLIN; ANLN","url":"https://www.omim.org/entry/616027"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nuclear speckles","reliability":"Supported"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"skeletal muscle","ntpm":26.6},{"tissue":"tongue","ntpm":14.8}],"url":"https://www.proteinatlas.org/search/PRKN"},"hgnc":{"alias_symbol":["PDJ","AR-JP","parkin"],"prev_symbol":["PARK2"]},"alphafold":{"accession":"O60260","domains":[{"cath_id":"3.10.20.90","chopping":"1-70","consensus_level":"high","plddt":87.3554,"start":1,"end":70},{"cath_id":"-","chopping":"247-364","consensus_level":"medium","plddt":88.7677,"start":247,"end":364},{"cath_id":"2.20.25","chopping":"414-460","consensus_level":"medium","plddt":87.8834,"start":414,"end":460}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O60260","model_url":"https://alphafold.ebi.ac.uk/files/AF-O60260-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O60260-F1-predicted_aligned_error_v6.png","plddt_mean":78.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PRKN","jax_strain_url":"https://www.jax.org/strain/search?query=PRKN"},"sequence":{"accession":"O60260","fasta_url":"https://rest.uniprot.org/uniprotkb/O60260.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O60260/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O60260"}},"corpus_meta":[{"pmid":"19029340","id":"PMC_19029340","title":"Parkin is recruited selectively to impaired mitochondria and promotes their autophagy.","date":"2008","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/19029340","citation_count":3329,"is_preprint":false},{"pmid":"20126261","id":"PMC_20126261","title":"PINK1 is selectively stabilized on impaired mitochondria to activate Parkin.","date":"2010","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/20126261","citation_count":2405,"is_preprint":false},{"pmid":"30135585","id":"PMC_30135585","title":"Parkin and PINK1 mitigate STING-induced inflammation.","date":"2018","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/30135585","citation_count":1074,"is_preprint":false},{"pmid":"26161729","id":"PMC_26161729","title":"Mechanism of phospho-ubiquitin-induced PARKIN activation.","date":"2015","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/26161729","citation_count":394,"is_preprint":false},{"pmid":"33168089","id":"PMC_33168089","title":"PINK1/PARKIN signalling in neurodegeneration and neuroinflammation.","date":"2020","source":"Acta neuropathologica communications","url":"https://pubmed.ncbi.nlm.nih.gov/33168089","citation_count":387,"is_preprint":false},{"pmid":"31177901","id":"PMC_31177901","title":"PHB2 (prohibitin 2) promotes PINK1-PRKN/Parkin-dependent mitophagy by the PARL-PGAM5-PINK1 axis.","date":"2019","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/31177901","citation_count":342,"is_preprint":false},{"pmid":"29995846","id":"PMC_29995846","title":"Mechanism of parkin activation by PINK1.","date":"2018","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/29995846","citation_count":318,"is_preprint":false},{"pmid":"24735649","id":"PMC_24735649","title":"Parkin and PINK1: much more than mitophagy.","date":"2014","source":"Trends in neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/24735649","citation_count":316,"is_preprint":false},{"pmid":"21194381","id":"PMC_21194381","title":"Targeting mitochondrial dysfunction: role for PINK1 and Parkin in mitochondrial quality control.","date":"2011","source":"Antioxidants & redox signaling","url":"https://pubmed.ncbi.nlm.nih.gov/21194381","citation_count":298,"is_preprint":false},{"pmid":"28437683","id":"PMC_28437683","title":"PINK1 and Parkin: emerging themes in mitochondrial homeostasis.","date":"2017","source":"Current opinion in cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/28437683","citation_count":275,"is_preprint":false},{"pmid":"27094585","id":"PMC_27094585","title":"Mechanisms of mitophagy: PINK1, Parkin, USP30 and beyond.","date":"2016","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/27094585","citation_count":265,"is_preprint":false},{"pmid":"29172924","id":"PMC_29172924","title":"PINK1-PRKN/PARK2 pathway of mitophagy is activated to protect against renal ischemia-reperfusion injury.","date":"2018","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/29172924","citation_count":260,"is_preprint":false},{"pmid":"27593930","id":"PMC_27593930","title":"Parkin and mitophagy in cancer.","date":"2016","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/27593930","citation_count":233,"is_preprint":false},{"pmid":"30100261","id":"PMC_30100261","title":"PINK1 and PARK2 Suppress Pancreatic Tumorigenesis through Control of Mitochondrial Iron-Mediated Immunometabolism.","date":"2018","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/30100261","citation_count":224,"is_preprint":false},{"pmid":"33570005","id":"PMC_33570005","title":"Regulation of PRKN-independent mitophagy.","date":"2021","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/33570005","citation_count":203,"is_preprint":false},{"pmid":"25612572","id":"PMC_25612572","title":"The mitochondrial protein BNIP3L is the substrate of PARK2 and mediates mitophagy in PINK1/PARK2 pathway.","date":"2015","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/25612572","citation_count":194,"is_preprint":false},{"pmid":"30290714","id":"PMC_30290714","title":"PRKN-regulated mitophagy and cellular senescence during COPD pathogenesis.","date":"2018","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/30290714","citation_count":192,"is_preprint":false},{"pmid":"25712550","id":"PMC_25712550","title":"Parkin structure and function.","date":"2015","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/25712550","citation_count":192,"is_preprint":false},{"pmid":"30115557","id":"PMC_30115557","title":"No Parkin Zone: Mitophagy without Parkin.","date":"2018","source":"Trends in cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/30115557","citation_count":190,"is_preprint":false},{"pmid":"32047033","id":"PMC_32047033","title":"Decision between mitophagy and apoptosis by Parkin via VDAC1 ubiquitination.","date":"2020","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/32047033","citation_count":187,"is_preprint":false},{"pmid":"21187721","id":"PMC_21187721","title":"Regulation of PINK1-Parkin-mediated mitophagy.","date":"2011","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/21187721","citation_count":154,"is_preprint":false},{"pmid":"29967542","id":"PMC_29967542","title":"Mechanism of parkin activation by phosphorylation.","date":"2018","source":"Nature structural & molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/29967542","citation_count":152,"is_preprint":false},{"pmid":"31339428","id":"PMC_31339428","title":"SQSTM1/p62 promotes mitochondrial ubiquitination independently of PINK1 and PRKN/parkin in mitophagy.","date":"2019","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/31339428","citation_count":145,"is_preprint":false},{"pmid":"29360040","id":"PMC_29360040","title":"Endosomal Rab cycles regulate Parkin-mediated mitophagy.","date":"2018","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/29360040","citation_count":141,"is_preprint":false},{"pmid":"33029617","id":"PMC_33029617","title":"Mitochondrial damage-associated inflammation highlights biomarkers in PRKN/PINK1 parkinsonism.","date":"2020","source":"Brain : a journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/33029617","citation_count":140,"is_preprint":false},{"pmid":"22956510","id":"PMC_22956510","title":"Systematic review and UK-based study of PARK2 (parkin), PINK1, PARK7 (DJ-1) and LRRK2 in early-onset Parkinson's disease.","date":"2012","source":"Movement disorders : official journal of the Movement Disorder Society","url":"https://pubmed.ncbi.nlm.nih.gov/22956510","citation_count":135,"is_preprint":false},{"pmid":"14976155","id":"PMC_14976155","title":"Parkin genetics: one model for Parkinson's disease.","date":"2004","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/14976155","citation_count":135,"is_preprint":false},{"pmid":"27679849","id":"PMC_27679849","title":"Miro phosphorylation sites regulate Parkin recruitment and mitochondrial motility.","date":"2016","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/27679849","citation_count":133,"is_preprint":false},{"pmid":"24878071","id":"PMC_24878071","title":"Functional interplay between Parkin and Drp1 in mitochondrial fission and clearance.","date":"2014","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/24878071","citation_count":131,"is_preprint":false},{"pmid":"28017782","id":"PMC_28017782","title":"Parkin and PINK1 functions in oxidative stress and neurodegeneration.","date":"2016","source":"Brain research bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/28017782","citation_count":125,"is_preprint":false},{"pmid":"31982458","id":"PMC_31982458","title":"The PINK1-Parkin axis: An Overview.","date":"2020","source":"Neuroscience research","url":"https://pubmed.ncbi.nlm.nih.gov/31982458","citation_count":115,"is_preprint":false},{"pmid":"30504269","id":"PMC_30504269","title":"Miro proteins prime mitochondria for Parkin translocation and mitophagy.","date":"2018","source":"The EMBO journal","url":"https://pubmed.ncbi.nlm.nih.gov/30504269","citation_count":114,"is_preprint":false},{"pmid":"31432739","id":"PMC_31432739","title":"USP33 deubiquitinates PRKN/parkin and antagonizes its role in mitophagy.","date":"2019","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/31432739","citation_count":112,"is_preprint":false},{"pmid":"15101042","id":"PMC_15101042","title":"Parkin gene alterations in hepatocellular carcinoma.","date":"2004","source":"Genes, chromosomes & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/15101042","citation_count":105,"is_preprint":false},{"pmid":"17052189","id":"PMC_17052189","title":"Parkin: a multifaceted ubiquitin ligase.","date":"2006","source":"Biochemical Society transactions","url":"https://pubmed.ncbi.nlm.nih.gov/17052189","citation_count":97,"is_preprint":false},{"pmid":"26975375","id":"PMC_26975375","title":"Parkin Regulates the Activity of Pyruvate Kinase M2.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26975375","citation_count":97,"is_preprint":false},{"pmid":"37207627","id":"PMC_37207627","title":"Unconventional initiation of PINK1/Parkin mitophagy by Optineurin.","date":"2023","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/37207627","citation_count":96,"is_preprint":false},{"pmid":"15229644","id":"PMC_15229644","title":"How does parkin ligate ubiquitin to Parkinson's disease?","date":"2004","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/15229644","citation_count":96,"is_preprint":false},{"pmid":"15189352","id":"PMC_15189352","title":"Parkin attenuates manganese-induced dopaminergic cell death.","date":"2004","source":"Journal of neurochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15189352","citation_count":95,"is_preprint":false},{"pmid":"30386443","id":"PMC_30386443","title":"PINK1-PARK2-mediated mitophagy in COPD and IPF pathogeneses.","date":"2018","source":"Inflammation and regeneration","url":"https://pubmed.ncbi.nlm.nih.gov/30386443","citation_count":94,"is_preprint":false},{"pmid":"15152079","id":"PMC_15152079","title":"Parkin and relatives: the RBR family of ubiquitin ligases.","date":"2004","source":"Physiological genomics","url":"https://pubmed.ncbi.nlm.nih.gov/15152079","citation_count":94,"is_preprint":false},{"pmid":"19483198","id":"PMC_19483198","title":"Parkin promotes intracellular Abeta1-42 clearance.","date":"2009","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19483198","citation_count":88,"is_preprint":false},{"pmid":"15571819","id":"PMC_15571819","title":"Ubiquitin, proteasome and parkin.","date":"2004","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/15571819","citation_count":87,"is_preprint":false},{"pmid":"27754761","id":"PMC_27754761","title":"A novel PINK1- and PARK2-dependent protective neuroimmune pathway in lethal sepsis.","date":"2016","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/27754761","citation_count":87,"is_preprint":false},{"pmid":"11470964","id":"PMC_11470964","title":"Parkin and Parkinson's disease.","date":"2001","source":"Current opinion in neurology","url":"https://pubmed.ncbi.nlm.nih.gov/11470964","citation_count":85,"is_preprint":false},{"pmid":"26611886","id":"PMC_26611886","title":"Parkin-dependent mitophagy in the heart.","date":"2015","source":"Journal of molecular and cellular cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/26611886","citation_count":78,"is_preprint":false},{"pmid":"26793099","id":"PMC_26793099","title":"Parkin Regulation and Neurodegenerative Disorders.","date":"2016","source":"Frontiers in aging neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/26793099","citation_count":71,"is_preprint":false},{"pmid":"14727181","id":"PMC_14727181","title":"Genetics of parkin-linked disease.","date":"2004","source":"Human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/14727181","citation_count":70,"is_preprint":false},{"pmid":"22388932","id":"PMC_22388932","title":"Regulation of parkin and PINK1 by neddylation.","date":"2012","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/22388932","citation_count":66,"is_preprint":false},{"pmid":"36803235","id":"PMC_36803235","title":"Hypoxia-induced GPCPD1 depalmitoylation triggers mitophagy via regulating PRKN-mediated ubiquitination of VDAC1.","date":"2023","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/36803235","citation_count":63,"is_preprint":false},{"pmid":"33685343","id":"PMC_33685343","title":"Mt-Keima detects PINK1-PRKN mitophagy in vivo with greater sensitivity than mito-QC.","date":"2021","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/33685343","citation_count":62,"is_preprint":false},{"pmid":"33572534","id":"PMC_33572534","title":"Interaction between Parkin and α-Synuclein in PARK2-Mediated Parkinson's Disease.","date":"2021","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/33572534","citation_count":61,"is_preprint":false},{"pmid":"17017531","id":"PMC_17017531","title":"Parkin and defective ubiquitination in Parkinson's disease.","date":"2006","source":"Journal of neural transmission. Supplementum","url":"https://pubmed.ncbi.nlm.nih.gov/17017531","citation_count":61,"is_preprint":false},{"pmid":"34671015","id":"PMC_34671015","title":"GAK and PRKCD are positive regulators of PRKN-independent mitophagy.","date":"2021","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/34671015","citation_count":60,"is_preprint":false},{"pmid":"35640906","id":"PMC_35640906","title":"Heterozygous PRKN mutations are common but do not increase the risk of Parkinson's disease.","date":"2022","source":"Brain : a journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/35640906","citation_count":59,"is_preprint":false},{"pmid":"11692161","id":"PMC_11692161","title":"Parkin is linked to the ubiquitin pathway.","date":"2001","source":"Journal of molecular medicine (Berlin, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/11692161","citation_count":58,"is_preprint":false},{"pmid":"35460111","id":"PMC_35460111","title":"Parkin Deficiency Impairs Mitochondrial DNA Dynamics and Propagates Inflammation.","date":"2022","source":"Movement disorders : official journal of the Movement Disorder Society","url":"https://pubmed.ncbi.nlm.nih.gov/35460111","citation_count":56,"is_preprint":false},{"pmid":"30074231","id":"PMC_30074231","title":"Loss of Microglial Parkin Inhibits Necroptosis and Contributes to Neuroinflammation.","date":"2018","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/30074231","citation_count":54,"is_preprint":false},{"pmid":"33448283","id":"PMC_33448283","title":"Assessing the relationship between monoallelic PRKN mutations and Parkinson's risk.","date":"2021","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33448283","citation_count":52,"is_preprint":false},{"pmid":"31333417","id":"PMC_31333417","title":"PARK2 Mutation Causes Metabolic Disturbances and Impaired Survival of Human iPSC-Derived Neurons.","date":"2019","source":"Frontiers in cellular neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/31333417","citation_count":51,"is_preprint":false},{"pmid":"19050041","id":"PMC_19050041","title":"Combined kinase inhibition modulates parkin inactivation.","date":"2008","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19050041","citation_count":51,"is_preprint":false},{"pmid":"22687462","id":"PMC_22687462","title":"Involvement and interplay of Parkin, PINK1, and DJ1 in neurodegenerative and neuroinflammatory disorders.","date":"2012","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/22687462","citation_count":49,"is_preprint":false},{"pmid":"37712850","id":"PMC_37712850","title":"PA2G4/EBP1 ubiquitination by PRKN/PARKIN promotes mitophagy protecting neuron death in cerebral ischemia.","date":"2023","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/37712850","citation_count":47,"is_preprint":false},{"pmid":"38553467","id":"PMC_38553467","title":"Genotype-phenotype correlation in PRKN-associated Parkinson's disease.","date":"2024","source":"NPJ Parkinson's disease","url":"https://pubmed.ncbi.nlm.nih.gov/38553467","citation_count":47,"is_preprint":false},{"pmid":"15078880","id":"PMC_15078880","title":"N-myc regulates parkin expression.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15078880","citation_count":47,"is_preprint":false},{"pmid":"12846978","id":"PMC_12846978","title":"Parkin and endoplasmic reticulum stress.","date":"2003","source":"Annals of the New York Academy of Sciences","url":"https://pubmed.ncbi.nlm.nih.gov/12846978","citation_count":47,"is_preprint":false},{"pmid":"28962651","id":"PMC_28962651","title":"Hexokinases link DJ-1 to the PINK1/parkin pathway.","date":"2017","source":"Molecular neurodegeneration","url":"https://pubmed.ncbi.nlm.nih.gov/28962651","citation_count":47,"is_preprint":false},{"pmid":"28222786","id":"PMC_28222786","title":"Post translational modification of Parkin.","date":"2017","source":"Biology direct","url":"https://pubmed.ncbi.nlm.nih.gov/28222786","citation_count":44,"is_preprint":false},{"pmid":"32297878","id":"PMC_32297878","title":"PINK1 and Parkin: team players in stress-induced mitophagy.","date":"2020","source":"Biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/32297878","citation_count":43,"is_preprint":false},{"pmid":"25700639","id":"PMC_25700639","title":"USP8 and PARK2/parkin-mediated mitophagy.","date":"2015","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/25700639","citation_count":42,"is_preprint":false},{"pmid":"29515107","id":"PMC_29515107","title":"PARK2 inhibits osteosarcoma cell growth through the JAK2/STAT3/VEGF signaling pathway.","date":"2018","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/29515107","citation_count":42,"is_preprint":false},{"pmid":"30911576","id":"PMC_30911576","title":"Metabolomics-based identification of metabolic alterations in PARK2.","date":"2019","source":"Annals of clinical and translational neurology","url":"https://pubmed.ncbi.nlm.nih.gov/30911576","citation_count":42,"is_preprint":false},{"pmid":"29040870","id":"PMC_29040870","title":"Parkin absence accelerates microtubule aging in dopaminergic neurons.","date":"2017","source":"Neurobiology of aging","url":"https://pubmed.ncbi.nlm.nih.gov/29040870","citation_count":41,"is_preprint":false},{"pmid":"25849928","id":"PMC_25849928","title":"Activation of the E3 ubiquitin ligase Parkin.","date":"2015","source":"Biochemical Society transactions","url":"https://pubmed.ncbi.nlm.nih.gov/25849928","citation_count":40,"is_preprint":false},{"pmid":"36333379","id":"PMC_36333379","title":"Parkin regulates adiposity by coordinating mitophagy with mitochondrial biogenesis in white adipocytes.","date":"2022","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/36333379","citation_count":39,"is_preprint":false},{"pmid":"25553463","id":"PMC_25553463","title":"Functions and characteristics of PINK1 and Parkin in cancer.","date":"2015","source":"Frontiers in bioscience (Landmark edition)","url":"https://pubmed.ncbi.nlm.nih.gov/25553463","citation_count":38,"is_preprint":false},{"pmid":"32892694","id":"PMC_32892694","title":"Two different axes CALCOCO2-RB1CC1 and OPTN-ATG9A initiate PRKN-mediated mitophagy.","date":"2020","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/32892694","citation_count":38,"is_preprint":false},{"pmid":"28335015","id":"PMC_28335015","title":"The synaptic function of parkin.","date":"2017","source":"Brain : a journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/28335015","citation_count":37,"is_preprint":false},{"pmid":"28620835","id":"PMC_28620835","title":"Twenty years since the discovery of the parkin gene.","date":"2017","source":"Journal of neural transmission (Vienna, Austria : 1996)","url":"https://pubmed.ncbi.nlm.nih.gov/28620835","citation_count":37,"is_preprint":false},{"pmid":"24162069","id":"PMC_24162069","title":"The reciprocal roles of PARK2 and mitofusins in mitophagy and mitochondrial spheroid formation.","date":"2013","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/24162069","citation_count":36,"is_preprint":false},{"pmid":"39300082","id":"PMC_39300082","title":"Activation of parkin by a molecular glue.","date":"2024","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/39300082","citation_count":35,"is_preprint":false},{"pmid":"35195911","id":"PMC_35195911","title":"RNA-binding protein YBX1 promotes brown adipogenesis and thermogenesis via PINK1/PRKN-mediated mitophagy.","date":"2022","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/35195911","citation_count":35,"is_preprint":false},{"pmid":"33565245","id":"PMC_33565245","title":"MITOL promotes cell survival by degrading Parkin during mitophagy.","date":"2021","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/33565245","citation_count":35,"is_preprint":false},{"pmid":"23939304","id":"PMC_23939304","title":"Loss-of-function rodent models for parkin and PINK1.","date":"2011","source":"Journal of Parkinson's disease","url":"https://pubmed.ncbi.nlm.nih.gov/23939304","citation_count":35,"is_preprint":false},{"pmid":"19285961","id":"PMC_19285961","title":"Regulation of DNA repair by parkin.","date":"2009","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/19285961","citation_count":35,"is_preprint":false},{"pmid":"38378758","id":"PMC_38378758","title":"A mutational atlas for Parkin proteostasis.","date":"2024","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/38378758","citation_count":34,"is_preprint":false},{"pmid":"33019842","id":"PMC_33019842","title":"PRCC-TFE3 fusion-mediated PRKN/parkin-dependent mitophagy promotes cell survival and proliferation in PRCC-TFE3 translocation renal cell carcinoma.","date":"2020","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/33019842","citation_count":34,"is_preprint":false},{"pmid":"39854875","id":"PMC_39854875","title":"Histone lactylation regulates PRKN-Mediated mitophagy to promote M2 Macrophage polarization in bladder cancer.","date":"2025","source":"International immunopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/39854875","citation_count":33,"is_preprint":false},{"pmid":"37926948","id":"PMC_37926948","title":"Long-Read Sequencing Resolves a Complex Structural Variant in PRKN Parkinson's Disease.","date":"2023","source":"Movement disorders : official journal of the Movement Disorder Society","url":"https://pubmed.ncbi.nlm.nih.gov/37926948","citation_count":32,"is_preprint":false},{"pmid":"31508359","id":"PMC_31508359","title":"PARK2 Suppresses Proliferation and Tumorigenicity in Non-small Cell Lung Cancer.","date":"2019","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/31508359","citation_count":31,"is_preprint":false},{"pmid":"16701203","id":"PMC_16701203","title":"Parkin blushed by PINK1.","date":"2006","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/16701203","citation_count":31,"is_preprint":false},{"pmid":"28038320","id":"PMC_28038320","title":"Pan-Cancer Analysis Links PARK2 to BCL-XL-Dependent Control of Apoptosis.","date":"2016","source":"Neoplasia (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/28038320","citation_count":29,"is_preprint":false},{"pmid":"25656612","id":"PMC_25656612","title":"Expression pattern of parkin isoforms in lung adenocarcinomas.","date":"2015","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/25656612","citation_count":29,"is_preprint":false},{"pmid":"39000117","id":"PMC_39000117","title":"Canagliflozin Mitigates Diabetic Cardiomyopathy through Enhanced PINK1-Parkin Mitophagy.","date":"2024","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/39000117","citation_count":28,"is_preprint":false},{"pmid":"28515082","id":"PMC_28515082","title":"Parkin-independent mitophagy-FKBP8 takes the stage.","date":"2017","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/28515082","citation_count":27,"is_preprint":false},{"pmid":"32088314","id":"PMC_32088314","title":"Bcl-xL inhibits PINK1/Parkin-dependent mitophagy by preventing mitochondrial Parkin accumulation.","date":"2020","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/32088314","citation_count":27,"is_preprint":false},{"pmid":"30697141","id":"PMC_30697141","title":"The Transcription Factor Function of Parkin: Breaking the Dogma.","date":"2019","source":"Frontiers in neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/30697141","citation_count":27,"is_preprint":false},{"pmid":"26992930","id":"PMC_26992930","title":"Central Parkin: The evolving role of Parkin in the heart.","date":"2016","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/26992930","citation_count":26,"is_preprint":false},{"pmid":"36803775","id":"PMC_36803775","title":"Parkin and mitochondrial signalling.","date":"2023","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/36803775","citation_count":25,"is_preprint":false},{"pmid":"33753174","id":"PMC_33753174","title":"A mechanistic review of Parkin activation.","date":"2021","source":"Biochimica et biophysica acta. General subjects","url":"https://pubmed.ncbi.nlm.nih.gov/33753174","citation_count":24,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":48123,"output_tokens":7737,"usd":0.130212,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":17154,"output_tokens":4716,"usd":0.101835,"stage2_stop_reason":"end_turn"},"total_usd":0.232047,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2008,\n      \"finding\": \"Parkin is selectively recruited from the cytosol to dysfunctional mitochondria with low membrane potential, after which it mediates engulfment of mitochondria by autophagosomes and their selective elimination (mitophagy).\",\n      \"method\": \"Live-cell imaging and mitochondrial membrane potential assays in mammalian cells with Parkin overexpression/loss-of-function\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — foundational direct localization experiment with functional consequence (mitophagy readout), replicated extensively across many subsequent labs\",\n      \"pmids\": [\"19029340\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"PINK1 accumulates selectively on damaged (depolarized) mitochondria via voltage-dependent proteolysis; PINK1 accumulation is both necessary and sufficient for Parkin recruitment to mitochondria, placing PINK1 upstream of Parkin in a linear epistatic pathway controlling mitophagy. Disease-causing mutations in PINK1 and Parkin disrupt Parkin recruitment at distinct steps.\",\n      \"method\": \"Genetic epistasis (PINK1/Parkin mutant cell lines), fluorescence microscopy, biochemical fractionation, Drosophila genetic rescue\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods, epistasis defined, replicated across labs\",\n      \"pmids\": [\"20126261\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Crystal structure of Parkin (Pediculus humanus ortholog) in complex with Ser65-phosphorylated ubiquitin (phosphoUb) reveals: (1) a conserved phosphate-binding pocket on RING1 that docks phosphoUb; (2) phosphoUb binding straightens a RING1 helix causing conformational changes that release the Ubl domain from the Parkin core; (3) Ubl release exposes Ubl Ser65 to PINK1 phosphorylation; (4) Ubl phosphorylation further stabilizes an open, active Parkin conformation. The Ubl domain acts as both an inhibitory and activating element.\",\n      \"method\": \"X-ray crystallography, mutagenesis, biochemical ubiquitination assays\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure plus mutagenesis plus functional assays in a single rigorous study\",\n      \"pmids\": [\"26161729\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Full activation mechanism of Parkin: hydrogen-deuterium exchange MS reveals large-scale domain rearrangement upon PINK1-mediated phosphorylation; the phospho-Ubl rebinds to the Parkin core at the unique parkin domain (UPD) using a phosphate-binding pocket (lined by AR-JP mutations), releasing the catalytic RING2 domain. A conserved linker 'activating element' (ACT) between Ubl and UPD mimics RING2 interactions to aid RING2 release. 1.8 Å crystal structure of phosphorylated human Parkin confirms this binding site.\",\n      \"method\": \"Hydrogen-deuterium exchange mass spectrometry, X-ray crystallography (1.8 Å), mutagenesis\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple orthogonal structural and biophysical methods, full-length human Parkin, rigorous mutagenesis validation\",\n      \"pmids\": [\"29995846\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Crystal structure of phosphorylated Bactrocera dorsalis Parkin in complex with phospho-ubiquitin and an E2 ubiquitin-conjugating enzyme reveals the key activating step: movement of the phospho-Ubl domain and release of the catalytic RING2 domain. HDX and NMR experiments confirm this mechanism extends to mammalian Parkin.\",\n      \"method\": \"X-ray crystallography, hydrogen/deuterium exchange, NMR, in vitro ubiquitination assays\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple orthogonal structural/biophysical methods, functional validation, independent replication of activation mechanism\",\n      \"pmids\": [\"29967542\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Parkin and PINK1-mediated mitophagy restrains innate immunity (STING-dependent type I interferon response). In Prkn−/− mice, exhaustive exercise or mtDNA mutation triggers inflammation that is completely rescued by concurrent STING loss. Loss of dopaminergic neurons and motor defects in aged Prkn−/−;mutator mice are also rescued by STING deletion.\",\n      \"method\": \"Mouse knockout models (Prkn−/−, Pink1−/−, STING−/−), exhaustive exercise stress, mtDNA mutator mouse, behavioral and histological analyses, cytokine measurements\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean genetic epistasis in multiple in vivo models, multiple orthogonal readouts, highly cited\",\n      \"pmids\": [\"30135585\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"BNIP3L/Nix is a substrate of PARK2/Parkin; Parkin ubiquitinates BNIP3L, which recruits NBR1 to mitochondria to target them for degradation. BNIP3L rescues mitochondrial defects in pink1 mutant Drosophila but not in park mutant Drosophila, placing BNIP3L downstream of Parkin.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assays, Drosophila genetic rescue, knockdown/overexpression in mammalian cells\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus genetic epistasis in Drosophila, single lab\",\n      \"pmids\": [\"25612572\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Parkin interacts with and ubiquitinates pyruvate kinase M2 (PKM2) both in vitro and in vivo; ubiquitination does not affect PKM2 stability but decreases its enzymatic activity, thereby regulating glycolysis. The interaction is enhanced during glucose starvation.\",\n      \"method\": \"Biochemical purification, Co-IP (in vitro and in vivo), ubiquitination assay, enzymatic activity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro and in vivo Co-IP plus enzymatic activity assay, single lab\",\n      \"pmids\": [\"26975375\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"PINK1 phosphorylation of Miro on S156 promotes Parkin interaction with Miro, stimulates Miro ubiquitination and degradation, recruits Parkin to mitochondria, and via Parkin arrests axonal transport of mitochondria. Phosphomimetic T298E/T299E on Miro inhibits PINK1-induced Miro ubiquitination and Parkin recruitment, acting dominantly over S156E.\",\n      \"method\": \"Phosphomimetic mutations, Co-IP, ubiquitination assays, axonal transport imaging in neurons\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — phosphomimetic mutagenesis plus functional transport assay, single lab\",\n      \"pmids\": [\"27679849\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Miro1 serves as a calcium-sensitive docking site for Parkin on mitochondria: a small pool of Parkin interacts with Miro1 before mitochondrial damage occurs, independently of PINK1 and without ubiquitination. After damage and PINK1 accumulation, this Parkin pool is activated, leading to Miro1 ubiquitination and degradation. Knockdown of Miro proteins reduces Parkin translocation and mitophagy. Miro1 EF-hand (calcium-sensing) domains control Miro1 ubiquitination and Parkin recruitment.\",\n      \"method\": \"Co-immunoprecipitation, fluorescence imaging, siRNA knockdown, EF-hand domain mutagenesis, mitophagy assays\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus domain mutagenesis plus mitophagy readout, single lab\",\n      \"pmids\": [\"30504269\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"USP33/VDU1 is a deubiquitinase for Parkin, localizes to the outer mitochondrial membrane, and removes K6-, K11-, K48-, and K63-linked ubiquitin conjugates from Parkin, predominantly at Lys435. USP33 knockdown increases both K48- and K63-linked Parkin ubiquitination, stabilizes Parkin, and enhances its translocation to depolarized mitochondria, increasing mitophagy.\",\n      \"method\": \"Co-IP, in vitro deubiquitination assays, site-directed mutagenesis (K435R), siRNA knockdown, mitophagy assays\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro DUB assay plus mutagenesis plus cellular mitophagy readout, single lab\",\n      \"pmids\": [\"31432739\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"USP8 deubiquitinase interacts with Parkin and preferentially removes K6-linked ubiquitin conjugates from Parkin. USP8 silencing leads to persistence of K6-linked Parkin ubiquitin conjugates, delaying Parkin translocation to damaged mitochondria and completion of mitophagy.\",\n      \"method\": \"Co-IP, ubiquitin linkage analysis, USP8 siRNA knockdown, mitophagy assays\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus functional mitophagy assay, single lab\",\n      \"pmids\": [\"25700639\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"VDAC1 is ubiquitinated by Parkin in a PINK1-dependent manner in two modes: monoubiquitination (at K274) and polyubiquitination. Polyubiquitination deficiency impairs mitophagy. Monoubiquitination deficiency (K274R) promotes apoptosis by augmenting mitochondrial calcium uptake through the MCU channel. A PD patient mutation T415N in Parkin lacks VDAC1 monoubiquitination activity while retaining polyubiquitination, and fails to rescue PD phenotypes in Drosophila.\",\n      \"method\": \"Ubiquitination assays, site-directed mutagenesis, calcium imaging, Drosophila transgenic models, patient mutation analysis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis plus in vivo Drosophila model plus calcium uptake assay, single lab\",\n      \"pmids\": [\"32047033\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"RABGEF1, an upstream regulator of the endosomal Rab GTPase cascade, is recruited to damaged mitochondria via ubiquitin binding downstream of Parkin. RABGEF1 directs RAB5 and RAB7A to damaged mitochondria; RAB7A depletion inhibits ATG9A vesicle assembly and subsequent encapsulation of mitochondria by autophagic membranes.\",\n      \"method\": \"siRNA knockdown, Co-IP, fluorescence microscopy in mammalian cultured cells, mitophagy assays\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus functional mitophagy readout with multiple knockdowns, single lab\",\n      \"pmids\": [\"29360040\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"PHB2 (prohibitin 2, inner mitochondrial membrane protein) is required for PINK1 stabilization on mitochondria and subsequent Parkin recruitment. PHB2 depletion destabilizes PINK1 and blocks Parkin, ubiquitin, and OPTN recruitment. The mechanism involves the PARL protease (activated upon PHB2 depletion) and PGAM5 (processed by PARL), defining a PHB2-PARL-PGAM5-PINK1 axis upstream of Parkin.\",\n      \"method\": \"siRNA knockdown, overexpression, Co-IP, fluorescence microscopy, mitophagy assays in MEFs and cancer cells\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple knockdown/overexpression experiments with mechanistic epistasis, single lab\",\n      \"pmids\": [\"31177901\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Parkin is neddylated (conjugated with NEDD8), and neddylation increases Parkin's E3 ligase activity. The PD neurotoxin MPP+ inhibits neddylation of Parkin. Expression of dAPP-BP1 (NEDD8 activation enzyme subunit) in Drosophila suppresses abnormalities induced by dPINK1 RNAi.\",\n      \"method\": \"Neddylation assays, E3 ligase activity assay, MPP+ treatment, Drosophila genetics\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical neddylation assay plus Drosophila genetic rescue, single lab\",\n      \"pmids\": [\"22388932\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Combined phosphorylation of Parkin by both casein kinase I and cyclin-dependent kinase 5 (Cdk5) decreases Parkin solubility, causing its aggregation and inactivation. Combined kinase inhibition partially reverses aggregation of pathogenic Parkin point mutants in cultured cells. Enhanced Parkin phosphorylation is detected in brain areas of sporadic PD patients, correlating with elevated p25 (Cdk5 activator) levels.\",\n      \"method\": \"Kinase activity assays, solubility fractionation, cell-based aggregation assays, immunohistochemistry of PD brain tissue\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in-cell kinase assays plus PD patient tissue, single lab\",\n      \"pmids\": [\"19050041\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Parkin ubiquitinates the Pael (parkin-associated endothelin receptor-like) receptor, an ER-resident protein prone to unfolding, using ER-resident E2s, and promotes its degradation, thereby suppressing ER stress-induced cell death. Insoluble Pael receptor accumulates in AR-JP patient brains.\",\n      \"method\": \"Yeast two-hybrid, in vitro ubiquitination assay with ER-resident E2s, cell death assays, post-mortem patient brain analysis\",\n      \"journal\": \"Annals of the New York Academy of Sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro ubiquitination assay plus cell-based rescue plus patient tissue, single lab\",\n      \"pmids\": [\"12846978\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Parkin promotes ubiquitination and proteasomal degradation of intracellular Aβ1-42. Parkin expression reduces intracellular Aβ1-42 levels and protects against its toxicity; incubation of Aβ1-42 cell lysates with ubiquitin in the presence of Parkin generates Aβ-ubiquitin complexes. Proteasomal inhibition blocks Parkin's effect on Aβ levels.\",\n      \"method\": \"Lentiviral overexpression, ubiquitination assay, proteasome inhibition, in vivo co-injection in rat motor cortex\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ubiquitination assay plus proteasome inhibition plus in vivo validation, single lab\",\n      \"pmids\": [\"19483198\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Parkin is essential for optimal DNA excision repair; parkin-deficient cells show reduced DNA excision repair restored by wild-type but not pathological mutant Parkin. Parkin interacts with PCNA (proliferating cell nuclear antigen), a coordinator of DNA excision repair.\",\n      \"method\": \"DNA repair assays, Co-IP with PCNA, transfection of wild-type vs. mutant Parkin, cell viability assays\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP plus repair assay, single lab, not replicated\",\n      \"pmids\": [\"19285961\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"PARK2/Parkin directly binds to and ubiquitinates BCL-XL, leading to its degradation. Inactivation of PARK2 leads to aberrant accumulation of BCL-XL in vitro and in vivo; cancer-specific PARK2 mutations abrogate BCL-XL ubiquitination. PARK2 modulates mitochondrial depolarization and apoptosis in a BCL-XL-dependent manner.\",\n      \"method\": \"Co-IP, ubiquitination assays, in vivo mouse models, cancer mutant analysis\",\n      \"journal\": \"Neoplasia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus ubiquitination assay plus in vivo model plus mutant analysis, single lab\",\n      \"pmids\": [\"28038320\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"MITOL/MARCH5 (mitochondrial ubiquitin ligase) ubiquitinates Parkin at lysine 220, promoting its proteasomal degradation. MITOL deletion leads to accumulation of phosphorylated active Parkin in the ER, resulting in FKBP38 degradation and enhanced cell death. MITOL thereby fine-tunes mitophagy by controlling Parkin quantity and blocks Parkin-induced cell death by protecting FKBP38.\",\n      \"method\": \"Ubiquitination assays, site-directed mutagenesis (K220), MITOL deletion cell lines, immunofluorescence, cell death assays\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis plus KO cell lines plus functional readouts, single lab\",\n      \"pmids\": [\"33565245\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PA2G4/EBP1 is ubiquitinated on lysine 376 by PRKN/Parkin on damaged mitochondria; ubiquitinated PA2G4 then interacts with SQSTM1/p62 to induce mitophagy, protecting neurons from cerebral ischemia-reperfusion injury.\",\n      \"method\": \"Co-IP, ubiquitination assay with site-directed mutagenesis (K376), neuron-specific knockout mice (MCAO model), AAV rescue\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis plus in vivo KO model plus rescue, single lab\",\n      \"pmids\": [\"37712850\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Parkin promotes Drp1-dependent mitochondrial fission by a mechanism requiring dephosphorylation of Drp1 serine 637 via the calcium/calmodulin/calcineurin pathway. Drp1 and Parkin are co-recruited to mitochondria in proximity of PINK1 following depolarization (FRET imaging). The outer mitochondrial adaptor MiD51 plays a major role in Drp1 recruitment and Parkin-dependent mitophagy.\",\n      \"method\": \"FRET imaging, calcineurin pathway inhibitors, Parkin/PINK1 mutant cell lines, mitochondrial morphology analysis\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — FRET imaging plus pharmacological pathway dissection, single lab\",\n      \"pmids\": [\"24878071\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Park2-deficient white adipocytes show reduced mitophagy but increased mitochondrial DNA content and mitochondrial function due to elevated mitochondrial biogenesis via Pgc1α stabilization through mitochondrial superoxide-activated Nqo1. Parkin therefore balances mitophagy and Pgc1α-mediated mitochondrial biogenesis in white adipocytes.\",\n      \"method\": \"Adipose tissue-specific Park2 knockout mice, mitophagy assays, Nqo1 overexpression, in vitro and in vivo metabolic assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — tissue-specific KO plus mechanistic pathway dissection, single lab\",\n      \"pmids\": [\"36333379\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Small molecule allosteric modulators act as 'molecular glues' enhancing phospho-ubiquitin (pUb) binding to and activation of Parkin. Crystal structure of Parkin–pUb complex with compound BIO-1975900 shows it binds next to pUb on RING0, contacting both proteins. HDX-MS confirms activation occurs via release of the catalytic Rcat domain. The compounds partially rescue activity of EOPD Parkin mutants R42P and V56E in organello and mitophagy assays.\",\n      \"method\": \"X-ray crystallography, isothermal titration calorimetry, ubiquitination assays, HDX-MS, organello and cell-based mitophagy assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure plus multiple biophysical methods plus functional assays with disease mutants, single rigorous study\",\n      \"pmids\": [\"39300082\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Parkin ubiquitinates synphilin-1 (the α-synuclein interacting protein); co-expression of α-synuclein, synphilin-1, and Parkin forms Lewy-body-like ubiquitin-positive cytosolic inclusions. Nitric oxide inhibits Parkin's E3 ligase activity and its neuroprotective function via S-nitrosylation both in vitro and in vivo.\",\n      \"method\": \"Ubiquitination assays, co-transfection/inclusion body formation assay, S-nitrosylation assay in vitro and in vivo\",\n      \"journal\": \"Journal of neural transmission. Supplementum\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple biochemical assays in vitro and in vivo, single review but citing primary experimental work\",\n      \"pmids\": [\"17017531\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Bcl-xL physically binds Parkin in the cytoplasm (FRET imaging) and also directly interacts with PINK1 on mitochondria (Co-IP), thereby inhibiting PINK1/Parkin-dependent mitophagy by preventing Parkin accumulation on mitochondria via two mechanisms: (1) cytoplasmic sequestration of Parkin, and (2) interference with PINK1 on the outer mitochondrial membrane.\",\n      \"method\": \"Co-IP, FRET imaging, FLIP analysis, Western blot, fluorescence microscopy in HeLa and HEK293T cells\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — Co-IP and FRET in single lab, no mutagenesis or reconstitution\",\n      \"pmids\": [\"32088314\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Parkin accelerates microtubule aging in its absence: PARK2 knockout mice show accelerated over-acetylation of the microtubule system in dopaminergic neurons and fibers, preceding mitochondrial transport defects. Parkin deficiency causes fragmentation of stable microtubules in PC12 cells and iPSC-derived midbrain neurons. Paclitaxel (microtubule-stabilizing agent) rescues mitochondrial mobility defects caused by Parkin loss.\",\n      \"method\": \"PARK2 KO mouse histology, immunofluorescence of acetylated tubulin, mitochondrial transport assays, paclitaxel rescue, iPSC-derived neurons\",\n      \"journal\": \"Neurobiology of aging\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo KO model plus cell-based rescue, single lab, two orthogonal model systems\",\n      \"pmids\": [\"29040870\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"Parkin functions as a RING-type E3 ubiquitin ligase (via its RING-IBR-RING motif), collaborating with E2 ubiquitin-conjugating enzymes UbcH7 or UbcH8. AR-JP patient mutations abolish parkin's E3 ligase activity. CDCrel-1, a synaptic vesicle-associated protein, was identified as a substrate for Parkin.\",\n      \"method\": \"In vitro ubiquitination assays with purified components, patient mutation analysis, substrate identification by biochemical pulldown\",\n      \"journal\": \"Journal of molecular medicine (Berlin, Germany)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution of E3 ligase activity, established by multiple labs\",\n      \"pmids\": [\"11692161\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"Parkin is an RBR-type E3 ubiquitin ligase that is maintained in an autoinhibited conformation; upon mitochondrial damage, PINK1 accumulates on depolarized mitochondria and phosphorylates ubiquitin (Ser65) and the Parkin ubiquitin-like (Ubl) domain (Ser65), causing phospho-ubiquitin to bind RING0 and release the Ubl, which then rebinds the unique parkin domain (UPD) via an activating element to liberate the catalytic RING2 domain, enabling Parkin to ubiquitinate outer mitochondrial membrane substrates (including Mfn1/2, Miro, VDAC1, BNIP3L, and others) and recruit autophagy receptors, thereby triggering selective mitophagy that suppresses STING-dependent innate immune activation; Parkin activity is further modulated by deubiquitinases (USP8 removing K6-linked, USP33 removing multiple linkages), by neddylation (increasing activity), by S-nitrosylation and phosphorylation by CKI/Cdk5 (inactivating), and by MITOL-mediated ubiquitination at K220 (promoting its own proteasomal degradation); beyond mitophagy, Parkin ubiquitinates additional substrates including BCL-XL, PKM2, synphilin-1, PCNA-associated repair proteins, and Aβ1-42, and also acts as a transcription factor, underscoring its multifunctional role in neuronal homeostasis and Parkinson's disease pathogenesis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PRKN/Parkin is a RING-IBR-RING (RBR)-type E3 ubiquitin ligase that operates as the effector arm of a quality-control pathway clearing damaged mitochondria by selective autophagy (mitophagy), with loss-of-function mutations causing autosomal-recessive juvenile Parkinsonism [#0, #29]. Parkin catalyzes ubiquitin transfer in collaboration with E2 conjugating enzymes (UbcH7/UbcH8), and AR-JP patient mutations abolish this activity [#29]. Mitochondrial depolarization causes PINK1 to accumulate on damaged organelles, where it is both necessary and sufficient to recruit cytosolic Parkin, placing PINK1 directly upstream in a linear pathway [#1]. Activation is conformational: PINK1 phosphorylates ubiquitin and the Parkin ubiquitin-like (Ubl) domain at Ser65; phospho-ubiquitin docks a RING1 pocket to release the autoinhibitory Ubl, and the phospho-Ubl then rebinds the unique parkin domain via a conserved activating element, liberating the catalytic RING2/Rcat domain for ubiquitin transfer [#2, #3, #4]. Once activated on the outer mitochondrial membrane, Parkin ubiquitinates a series of substrates including Miro1, VDAC1, and BNIP3L/Nix to mark mitochondria for clearance, arrest their axonal transport, and recruit autophagy receptors and the endosomal Rab cascade (RABGEF1–RAB5/RAB7A) that drives autophagic engulfment [#6, #8, #9, #12, #13]. This mitophagy program restrains STING-dependent type I interferon innate immunity, and its failure drives inflammation and dopaminergic neuron loss in vivo [#5]. Parkin activity is tuned by deubiquitinases that reverse its self-ubiquitination (USP8 removing K6-linked, USP33 removing multiple linkages to stabilize Parkin) [#10, #11], by activating neddylation [#15], and by inactivating modifications including CKI/Cdk5 phosphorylation and S-nitrosylation [#16, #26]; MITOL/MARCH5 ubiquitinates Parkin at K220 to control its abundance [#21]. Beyond mitophagy, Parkin ubiquitinates additional substrates affecting metabolism and survival, including PKM2, BCL-XL, the Pael receptor, synphilin-1, and intracellular Aβ1-42 [#7, #17, #18, #20, #26]. Small-molecule 'molecular glues' that enhance phospho-ubiquitin binding to RING0 can pharmacologically activate Parkin and partially rescue early-onset PD mutants [#25].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established Parkin's core biochemical identity as a RING-type E3 ubiquitin ligase whose activity is destroyed by disease mutations, defining the molecular lesion in AR-JP.\",\n      \"evidence\": \"In vitro ubiquitination reconstitution with purified components, E2 pairing, and patient mutation analysis\",\n      \"pmids\": [\"11692161\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"CDCrel-1 substrate relevance to neurodegeneration unresolved\", \"did not define the physiological trigger for ligase activity\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Revealed that Parkin's function is spatially gated — it is recruited from cytosol specifically to depolarized mitochondria and drives their autophagic elimination, linking the ligase to organelle quality control.\",\n      \"evidence\": \"Live-cell imaging and membrane-potential assays in mammalian cells\",\n      \"pmids\": [\"19029340\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"did not identify the upstream sensor of damage\", \"OMM substrates ubiquitinated for mitophagy not yet mapped\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Placed PINK1 upstream of Parkin by showing voltage-dependent PINK1 accumulation is necessary and sufficient for Parkin recruitment, defining a linear PINK1–Parkin mitophagy pathway.\",\n      \"evidence\": \"Genetic epistasis, microscopy, fractionation, Drosophila rescue\",\n      \"pmids\": [\"20126261\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"molecular signal transmitted from PINK1 to Parkin unknown at this stage\", \"did not resolve the conformational activation mechanism\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Solved how phospho-ubiquitin acts as the activating ligand, docking RING1 to release the autoinhibitory Ubl and exposing Ubl Ser65 for further phosphorylation — explaining the feed-forward activation switch.\",\n      \"evidence\": \"X-ray crystallography of Parkin–phosphoUb complex with mutagenesis and ubiquitination assays\",\n      \"pmids\": [\"26161729\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"did not show fate of released RING2 catalytic domain\", \"ortholog structure required mammalian confirmation\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Completed the activation model by showing the phospho-Ubl rebinds the UPD via a conserved activating element to release the catalytic RING2/Rcat domain, with full-length human and insect structures plus E2 capture.\",\n      \"evidence\": \"HDX-MS, 1.8 Å and complex crystallography, NMR, mutagenesis, in vitro ubiquitination\",\n      \"pmids\": [\"29995846\", \"29967542\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"substrate engagement geometry on the mitochondrial surface not resolved\", \"kinetics of activation in cellulo not quantified\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identified downstream effectors converting Parkin ubiquitination into autophagic engulfment, recruiting the RABGEF1–RAB5/RAB7A endosomal cascade and ATG9A vesicle assembly to damaged mitochondria.\",\n      \"evidence\": \"siRNA knockdown, Co-IP, microscopy, mitophagy assays in cultured cells\",\n      \"pmids\": [\"29360040\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"single lab; direct ubiquitin substrate recruiting RABGEF1 not defined\", \"reciprocal validation absent\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Resolved the upstream control of PINK1 stability, defining a PHB2–PARL–PGAM5 axis required to stabilize PINK1 and thereby permit Parkin and OPTN recruitment.\",\n      \"evidence\": \"Knockdown/overexpression epistasis, Co-IP, microscopy, mitophagy assays\",\n      \"pmids\": [\"31177901\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"single lab\", \"direct biochemical interactions within the axis not fully reconstituted\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Defined Miro as both a docking platform and a substrate, showing PINK1 phosphorylation of Miro promotes Parkin binding, Miro ubiquitination/degradation and arrest of mitochondrial axonal transport.\",\n      \"evidence\": \"Phosphomimetic mutagenesis, Co-IP, ubiquitination assays, axonal transport imaging; plus calcium-sensitive docking via Miro1 EF-hands\",\n      \"pmids\": [\"27679849\", \"30504269\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"single lab per study\", \"stoichiometry of the pre-damage Parkin–Miro pool unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Showed VDAC1 ubiquitination is dual-mode, with mono- versus poly-ubiquitination separating mitophagy from calcium/apoptosis control, validated by a PD mutation selectively losing monoubiquitination.\",\n      \"evidence\": \"Mutagenesis, calcium imaging, Drosophila models, patient mutation analysis\",\n      \"pmids\": [\"32047033\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"single lab\", \"mechanism linking monoUb to MCU calcium flux not fully defined\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Connected Parkin-driven mitophagy to suppression of innate immunity, showing STING deletion rescues inflammation and dopaminergic neuron loss in Prkn-deficient stressed mice.\",\n      \"evidence\": \"Multiple mouse knockout models, exercise/mtDNA-mutator stress, behavioral and histological readouts\",\n      \"pmids\": [\"30135585\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"molecular route from defective mitophagy to STING activation not fully detailed\", \"human relevance of the inflammatory axis untested here\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified regulators tuning Parkin levels and modification state — deubiquitinases (USP8, USP33), activating neddylation, inactivating CKI/Cdk5 phosphorylation and S-nitrosylation, and MITOL-mediated K220 ubiquitination controlling Parkin turnover.\",\n      \"evidence\": \"Deubiquitination/neddylation/kinase assays, mutagenesis, KO cell lines, mitophagy and cell-death readouts, PD tissue\",\n      \"pmids\": [\"25700639\", \"31432739\", \"22388932\", \"19050041\", \"17017531\", \"33565245\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"each modification largely from a single lab\", \"integrated hierarchy of these regulatory inputs unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Expanded Parkin's substrate repertoire beyond canonical mitophagy to metabolic, apoptotic, ER-stress, and proteostatic targets (PKM2, BCL-XL, Pael receptor, synphilin-1, Aβ1-42, PA2G4, BNIP3L), broadening its role in neuronal and metabolic homeostasis.\",\n      \"evidence\": \"Co-IP, ubiquitination assays, in vivo KO/rescue models across multiple studies\",\n      \"pmids\": [\"26975375\", \"28038320\", \"12846978\", \"17017531\", \"19483198\", \"37712850\", \"25612572\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"substrate specificity determinants in vivo unclear\", \"relative physiological weight of mitophagy versus non-mitochondrial substrates unresolved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Demonstrated Parkin is pharmacologically tractable, with small-molecule molecular glues enhancing phospho-ubiquitin binding at RING0 to activate the enzyme and partially rescue early-onset PD mutants.\",\n      \"evidence\": \"Crystallography, ITC, HDX-MS, ubiquitination and mitophagy assays with disease mutants\",\n      \"pmids\": [\"39300082\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"in vivo efficacy and selectivity not established\", \"rescue of only a subset of disease mutants\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How Parkin's diverse substrate selection and regulatory modifications are integrated in vivo to balance mitophagy, mitochondrial biogenesis, metabolism, and neuronal survival remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"no unified model ranking the physiological importance of competing substrates\", \"tissue-specific regulatory hierarchy of activating/inactivating modifications undefined\", \"structural basis of substrate engagement on the mitochondrial surface unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [29, 2, 3]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [29, 6, 7, 12, 20]},\n      {\"term_id\": \"GO:0031386\", \"supporting_discovery_ids\": [29, 6, 12]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [25]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 9, 27]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0, 1, 9, 12]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [0, 1, 6, 13]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [23, 24]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [29, 10, 21]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [20, 21, 12]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"PINK1\", \"Miro1\", \"VDAC1\", \"BNIP3L\", \"BCL-XL\", \"USP8\", \"USP33\", \"PKM2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":9,"faith_pct":88.88888888888889}}